The present disclosure relates to an imaging device and an imaging method. More particularly, the present disclosure relates to an imaging device and an imaging method that make it possible to calculate an illuminance with higher accuracy.
In recent years, miniaturization and higher functionality of a cellular phone, a digital camera, and the like are in progress. Power consumption increases due to the higher functionality, and hence measures are taken to achieve low power consumption. With the progress of miniaturization, measures are taken to achieve miniaturization of the battery or the like. In the cellular phone or the like, regarding the brightness of an LCD or key light, a high-luminance design is employed such that the LCD or the key light can be easily viewed also in a dark place. However, achieving high luminance increases power consumption. Therefore, a luminance sensor is provided. Based on a luminance data item determined by the illuminance sensor, the luminance of the LCD or the key light is adjusted to optimize the illuminance. In this way, a reduction of power consumption is achieved.
However, for this purpose, it is necessary to install an illuminance sensor into a terminal. A position at which the illuminance sensor is installed has to be suitable for illuminance measurement, and hence has a large constraint on mounting. Further, a design of a screen for receiving light is also necessary, and hence it becomes a constraint on not only mounting but also design. As techniques in the related art that are aimed to implement functions of an illuminance sensor and a camera module with small space, there are cellular phones disclosed in Japanese Patent Application Laid-open No. 2003-110681, Japanese Patent Application Laid-open No. 2008-042846, and Japanese Patent Application Laid-open No. 2002-300447 (hereinafter, referred to as Patent Documents 1, 2, and 3, respectively).